JPS58143361A - Developing device - Google Patents

Abstract

PURPOSE:To contol the layer thickness of a developer to a prescribed value over a long period, by constituting a titled device so that a layer thickness control means has a magnetic material having fluidity, and a flexible member placed between this magnetic material and a developer carrying body. CONSTITUTION:When a copying operation is started, a photoreceptor 1 is driven in the direction as indicated with an arrow A, an electrostatic latent image is formed, and its latent image moves to a developing area D. On the other hand, in a developing device, a developing sleeve 7 is rotated and driven counterclockwise, and also a magnet 8 is rotated and driven clockwise, by which a toner 5 in a tank 6 is fed out of the tank 6, is carried counterclockwise while being carried by the developing sleeve 7, and the toner passes through a controlled area where a film 12 is brought into contact with the sleeve through the toner. In this case, a magnetic fluid 11 in a vessel 10 is attracted by magnetic force generated by the magnet 8 provided in the developing sleeve 7, the toner between the film 12 and the sleeve 7 is pressed through the film 12, therefore, the quantity of the toner passing through the controlled area is controlled by the pressing action caused by the magnetic fluid 11.

Description

[Detailed description of the invention]

The developer carrier has a layer thickness regulating means for regulating the layer thickness of the developer, and the layer thickness is regulated and the developer is conveyed to a development area where the latent image is visualized. The present invention also relates to a developing device that visualizes the latent image. Developing devices of the above type for use in electronic copying machines, electrostatic recording devices, magnetic printers, and other various recording devices are well known in the art. In this type of developing device, various types of developers are used, such as a two-component developer containing toner and a carrier, or a two-component developer containing no carrier. When using a developer, it is necessary to control the layer thickness of the developer before it is used for development using a layer thickness regulating means. In particular, in a developing device that uses a two-component developer made of high-resistance toner, the developer is forcibly used before being applied to the image. π, which requires charging
Therefore, the thickness of the developer must be kept extremely thin and the thickness of the developer must be controlled as uniformly as possible by the layer thickness regulating means, and the role played by the layer thickness regulating means is particularly important. When charging a developer made of high resistance 1.0-, if it is thick,
It becomes easier to charge this material uniformly over its entire thickness. In order to meet the above requirements, various types of layer thickness regulating means have been proposed and put into practical use, such as a doctor blade placed close to the developer carrier, or a developing device on the developer carrier. A typical example is a structure in which a layer thickness regulating member consisting of an elastic blade that presses the agent is used as a layer thickness regulating means. In this case, in the conventional layer thickness regulating means, a relatively small area portion of the layer thickness regulating member is brought into contact with the developer to regulate the layer thickness. In order to obtain the layer thickness regulating effect, the layer thickness regulating member must be pressed against the developer with a large force. However, when the contact pressure between the layer thickness regulating member and the developer is increased in this way, an unreasonable external force acts on the developer, which accelerates the deterioration of the developer. There is a risk that the image quality of f♀'' may deteriorate.Not only that, but as a result of wear of the developer carrier and the layer thickness regulating member, the fatigue of the layer thickness regulating member against the developer carrier may be reduced. The position changes over time from the initial installation state, and it is extremely difficult to regulate the developer layer thickness to a predetermined thickness over a long period of time.The invention eliminates the above-mentioned conventional drawbacks. It is an object of the present invention to provide an imaging device capable of reducing the external cost. Hereinafter, the invention will be applied to an electronic copying machine and an image device #
However, as explained earlier, in a developing device using a two-component developer made of high-resistance toner, the role played by the layer thickness regulating means is particularly important. Special features for viewing devices that use agents [
Can be applied to advantage. In consideration of this point, in the following embodiments, a developing device using a one-component leveling agent made of a magnetic toner having a relatively high specific volume resistivity as described later will be explained. ! : to make. FIG. 1 shows an endless belt-like photoreceptor 1.1, which is composed of a latent image carrier, and a developing device that visualizes an electrostatic latent image formed on the surface of the photoreceptor 1. 2bi-shown. A belt-shaped photoreceptor J is wound around two rollers 3 and 4 shown in the figure and another roller not shown, so that it can be rotated σ in the direction of arrow A. Instead of the belt-shaped photoreceptor 1,
Of course, it is possible to use a sorted or drum-shaped photoreceptor. The developing device 2 consists of a tank 6 containing a two-component developer made of high-resistance magnetic 1 and 5, and a developing bath IJ 1 tube 7. It has a magnetic field generating means consisting of a roller-shaped magnet 8, and a layer thickness regulating means 9, which will be explained in detail later. In an exceptional case, the developing sleeve 7 can be
Although it is in pressure contact with the belt-shaped photoreceptor, it is also possible to arrange the photoreceptor and sleeve 7 with a predetermined minute gap between them. 7 is rotationally driven in the counterclockwise direction, and magnet 8 is)
'i li'i]
C7? -) However, it is of course possible to make only the developing tube 11-7 or the magnet 8 stop rotating. Each magnetic pole S of the magnet 8. N has a polarity opposite to that of Letter Jr along the circumferential direction of the developing sleeve 7. In exceptional cases, the layer thickness regulating means 9 is a container]Of7? :Accommodation 8re7? It consists of a "liquid calendar fluid 1" and a flexible film 12 provided at the opening of the developing tube 7 of the container 1 (), and the periphery of this film 12 ( Container 10
This has been fixed. Container] 0, together with the membrane 12,
1f (-1) is sealed to prevent the magnetic fluid from leaking out of the container.
Through the toner existing between the sleeve 7 and the sleeve 7, contact is made in a planar manner over almost the entire length of the sleeve 7 (in this case, the lighting film 2 and the sleeve 7 The contact length ζL is as long as the length of contact with the developing sleeve 7 via the conventionally known layer thickness regulating member or toner, preferably 1.
(Lr·I+11'-J,, set to 0). When the copying operation is started, the photoreceptor 1 is driven in the direction of the arrow, and at this time, an electrostatic latent image is formed on the surface of the photoreceptor by a latent image forming means (not shown), thus forming a 1ζ latent image. Then, the toner moves to the contact area, that is, the development area, through the image sleeve (7) and the toner body. On the other hand, in the developing device, the developing sleeve 7 is rotated counterclockwise, and the magnet 8 is rotated clockwise.
As a result, the toner 5 in the tank 6 is sent out of the tank, and carried by the developing sleeve 7 in a direction counterclockwise in the figure. The toner transported in this way is
The membrane] 2 passes through the region (regulating region) where the sleeve [+-] contacts via the sleeve. At this time, for the magnetic fluid in the container 10,
σ 1 ζ i'h stone 8 installed in the developing sleeve 7 Vrc,
J: Attracted by magnetic force, membrane 2 and sleeve 7
The toner between the two is pressed through the membrane 12. Therefore, the amount of toner passing through the regulated area is controlled by the pressing action of the magnetic fluid.
The first layer 5a of the sleeve 7 has a thinner thickness ζ. The effect of this layer thickness regulation will be explained in more detail later. The thickness of the child's shell should be thinned and the left toner should be 5 layers thick. Subsequently, while being held by the developing sleeve 70:1'+4, it is conveyed in the counterclockwise direction and reaches the development area described above. This and p
, the toner on the image sleeve 70 is in a known form, and is electrostatically attached to the electrostatic image on the photoreceptor 1, so that the latent image becomes a visible image (
This bendable image is then transferred to a transfer material (as shown) by a transfer device (as shown in the figure). Ru. After passing through the 1st image and 10 areas, the latent image is transferred to tank 6 again.The latent image is visualized as a child series. , At that time, -・
In example N, a toner with a high specific volume resistivity is used as the developer, so in order to enable nJ visualization of the latent image as described above, the toner before reaching the development area is It is necessary to forcibly charge the polarity of the legs. This charging can be carried out by any suitable method known per se,
For example, friction between the surface of the developing sleeve 70 and the toner, friction between the film 12 of the layer thickness regulating means 9 or other charging member (not shown) and the toner 2-, or charge on the toner by a corona discharger (not shown). Even when charging the toner with the force described in step 1, the toner layer on the developing sleeve 70 can be made as thin as possible by the layer thickness regulating means 9, so that the layer thickness can be reduced. It would be possible to charge l゛j−j− over the entire area.However, it is necessary to forcibly charge σ
) The specific volume resistivity of a certain toner is usually ]010ΩQ
ll to 10, special IF-]013 to] 0'',Q
-cm or more, and when using a toner with a lower specific volume resistivity, this l-, toner is in the developing area Dv
At C, the latent image is charged by electrostatic induction due to the charge of the latent image. The developing operation is generally performed as described below.Next, the action of layer thickness regulation by the single layer thickness regulation means 9 will be explained in more detail in (I) to Bamboo, and the advantages of the invention will be made clear. . (T) As already mentioned, the length of the film 12 that contacts the developing sleeve 7 through the 1st hole is quite long, and this toner is pressed by the magnetic fluid H. It takes a relatively long time for the film 12r to exert its regulating action.Therefore, if the force with which the film 12 presses the toner is the pressure contact force per unit area of the film J2, this pressure contact force will be U
Even if the pressing force per unit area applied to the toner by conventional doctor blades or elastic blades is much smaller, the thickness ζ of one layer of toner can be controlled to approximately a constant r9T. Since the stress generated on the k and l toners is small σ<, the deterioration of the toner can be effectively suppressed. In addition, since the generation of frictional heat is suppressed, the temperature of the toner can be kept low, and the inconvenience of the toner being thermally fused to the film 12 can be reduced. The toner melts on the film 12, and this adheres to the film 12, causing the toner to be fused and dislocated. This is inevitable, and if such a situation occurs, the quality of the visible image will be significantly impaired. - Since the membrane 12 presses the toner on the sleeve 70 through the toner, the membrane 12 comes into contact with the surface of the sleeve 7 through the toner with an average pressure over its entire contact surface. The thickness of one layer will be uniform throughout, and there will be no locally extremely thick areas or extremely thin VC areas.In this case,
There are a lot of unevenness on the surface of the developing sleeve 7.
Even so, since the film 12 tends to adhere closely to the sleeve along the unevenness, the uniformity of the toner thickness is not significantly impaired by the unevenness. 1 to membrane] 2 to container 10

[When you can say a few words, this membrane is 12VC
If virtually no tension is applied, the film [2] can almost freely change its shape by itself according to the surface condition of the sleeve while being pressed against the magnetic fluid [1] during operation of the developing device. Therefore, the above-mentioned effect can be obtained more reliably. If the inverse VC film J2 is given the same tension in its plane in advance, in addition to the suppressing force of the magnetic fluid J1, the film]2
It is possible to enhance the thinning effect of the 'e''-'' toner by applying pressure to the toner using the tension. Whether or not to apply tension to the membrane] 2 in advance may be appropriately selected each time as necessary. fall (as explained in Section 1 and in Section 1, the pressing force of the membrane 12 against the toner is relatively small;
11g1 A small dog scolding Shiotsu Haibai (lX, ×+h
@ ] It is possible to minimize the wear of 2. ! ! Even if the film 12 is somewhat worn over time due to the friction l/i' with the toner in 1, the film 12 is almost completely or mainly pressed against the toner by the magnetic force acting on the magnetic fluid. Therefore, this pushing force +1 does not vary significantly from the initial setting value. With J', the toner layer can be regulated to approximately a predetermined thickness ζ over a long period of time. ■ Dr.Frede, which has been used in the past, uses a scraper to control the layer thickness of the toner in the developing sleeve 10. If the doctor blade is pressed loudly against the toner, there is a risk that the above-mentioned streaks extending in the circumferential direction of the developing sleeve will appear on the toner after regulation. First, it is not easy to adjust the pressure of the doctor blade against the toner so that the above-mentioned smudge does not occur. Rather than regulating the thickness, the layer thickness is regulated by pushing the toner into the sleeve 7, so the pressing force of the membrane J2 against the toner is increased, and even when a woman is using the toner, the toner layer 5a [as described above] is There is almost no sagging.When the pressing force of one membrane 12 reaches the level at 1, there is a gap between the membrane 12 (!-sleeve 7) as schematically shown in FIG. Even if substantially one layer of toner 5 remains and the pressing force of the membrane 2 is further increased in this state,
The thickness of the toner layer between the belt and the sleeve does not become any thinner, so no sagging occurs. Therefore, it is possible to regulate the toner layer to be extremely thin without paying any conventional consideration to adjusting the pressure contact force of the membrane 12 against the toner. When the developing sleeve 7 or film 2 passes through the toner contact area), the toner is frictionally charged by friction with the toner! ζζAttachment The contact length Y of the membrane mentioned above is relatively long, and the [・na is salt 11
It takes a relatively long time to pass through the area No. 11, so that the toner can be effectively charged. And ([■)
As mentioned in 1, the thickness of the toner layer can be made uniform, and what's more!・The toner can be made extremely thin, for example, as thick as the toner (see Figure 21)/ζ, and the difference in the amount of charge between each toner particle is reduced to 1 < (1411, uniformly charged). Therefore, there is less background dirt and excellent sharpness. - It is possible to collapse the visible image. Is it possible to control the amount of charge on the toner by adjusting the magnitude of the pressing force of the film J2 against the UshiP toner? If a conventional layer thickness regulating member is used and VC is 1, the amount of charge on the toner can be controlled to adjust the amount of charge on the toner. When the pressing force of the member is varied,
Even if the thickness of the toner layer is 35, it is only one layer. Therefore, it is difficult to maintain one of the toner charge amount and toner layer thickness at approximately the same level and adjust only the other. In the r layer thickness regulating means 9 shown in FIG.
Since the thickness of the first layer does not change, if the pressing force of the membrane J2 is set to VrC above this level, it is necessary to keep the thickness of the toner layer almost constant and adjust only the amount of charge. - Is it possible? Ru. MP toner passes through regulation area 4-. In order to cause the toner to be triboelectrically charged in J-p, three methods can be considered. [111ぢ, ■ Toner particle cultivation sleeve 7
(Charging the toner particles and the film) 2 (Charging the toner due to the friction between the developing sleeve 7 and the film) The above three methods can be adopted as appropriate by selecting the material of the film 2 or the image sleeve 7 to be a triboelectric type so as to be able to impart a charge of the required polarity to the toner. In this case, Yoshiai, who adopts the method of , ■ or ■, has the advantage of constructing the membrane 12 from a conductive material and grounding the wire membrane 12. The reason for this is as follows. [ 1 [1, film] 2 is charged to the opposite polarity to the toner, but
At that time, if the film J2 is made of an insulating material,
Then, over time, the charge accumulates at 12 (!
-, and the triboelectric charging efficiency of this left-handed toner gradually decreases. Since the music roller is made of a membrane 12η- conductive material, the electric charge that accumulates in this membrane and acts on the IC can be released.・It is possible to prevent a decrease in the triboelectric charging efficiency of the toner. 11, from the viewpoint of increasing the charging efficiency of the toner, it is advantageous to adopt the method (2).The toner is charged by the friction between the film J2 and the toner, as described above, by field 8. The material of the membrane must be selected, and seven complications must be considered.
In case 8IL, it is advantageous to adopt method (2). As explained in detail in (I) to ■,
Use of the layer thickness regulating means 9 shown in FIG. 1 provides various advantages. By the way, in the embodiment shown in FIG.
A liquid magnetic fluid is used as the magnetic material to push the toner through the medium, but instead of using such a fluid, other external bodies with fluidity, such as magnetic powder made of particles of minute diameter, can be used. In g-4, such a powder is used and 1).
Although it is possible to use an appropriate powder other than this J14. When using a leveling agent with flb properties in an imaging device, the developer itself can also be used as a magnetic powder in the layer thickness regulating means V (Fig. 3 is an example of this). , and the kN layer thickness regulating means shown here is located within the tank 6 containing the magnetic toner 5.
It is locked in. In some cases, the film J2 also passes through the toner 1.
and comes into contact with the surface of the developing sleeve 7, and the opposite side of the line film] 2
A large amount of toner 5 is stored in the toner storage portion 15 1111 . The toner in this container] 5 is drawn by a magnet of 8 VC through the developing sleeve 7, which suppresses the toner passing between the film J2 and the sleeve 7, as shown in FIG. Exactly the same VC as in the real 7iti example
(The -C toner is thinned.
1ζ To stop the toner from decreasing by 19'li, in some cases, form a slit 6 in the lower half of the membrane 2, and through this slit lfi%, the toner is stored in the storage part] 5
[7z] so that it can be packed into (arrow 13). Instead of this slit, [Dopa J2's F') 5 is shaped into a mesh, and the toner is accommodated through the mesh 4] 5
According to experiments, in the configuration shown in Fig. 3, tension is applied to the membrane] 2 in advance, and this tensile magnetic force,!
Press 1.su~ between sleeves 7 and press 1F so that the left side is
!・Women are advantageous because they can make the layer thinner and enhance its charging effect. At that time, the size of the toner layer after regulation was 31 te, which was 19 nets, which was about the same as the round trip. In the embodiment VC shown in FIG. 1 and FIG. An IC that allows the suppressing force of the magnetic material to be uniformly transmitted over 1.
However, if only a flexible member consisting of the membrane J2 is used, and this membrane J2 is used for a long period of time, the surface of the line membrane 2 may be scratched due to the friction of the toner being transported. ), there is a risk that the above-mentioned streaks will form and break even more after the regulation. In consideration of this point, in the embodiment shown in FIG. It is provided. Then, this belt]7 is wound around the supply roller J8 in a roll shape, and the toner on the sleeve 7 is transferred to the supply roller J8. There are scratches on the part of the belt 17 that comes in contact with the belt, and the lever has deteriorated.
', P is sent out, the new belt part (that is, deteriorated) is brought into contact with the toner on the sleeve 7, and the deteriorated female belt part can be wound around another roller]9. In this way, a new portion of the flexible member can always be brought into pressure contact with the toner, thereby preventing the inconvenience of the toner becoming more sticky. For the same purpose, in the embodiment shown in FIG.
It is wrapped around 2. With this configuration, the part of the belt 17 that contacts the sleeve 7 through the toner deteriorates, resulting in c! -'t vc , the belt 17f can be driven to place a new belt Htx on the sleeve 7 in an opposing manner. Alternatively, the belt J7 shown in FIG. 5 may be constantly driven in an appropriate direction during the operation of the developing device. In the embodiment shown in FIGS. 4 and 5, two flexible members are used, the membrane J2 and the belt 17, and in the configuration shown in FIG. is omitted, and the belt itself functions to prevent the magnetic fluid H from flowing out from the container. In this case, the belt 17 is driven and expanded as necessary, so in order to prevent the magnetic fluid from leaking between the belt J7 and the container. ]7 to the container]0[sealing suppressing member to press 23.
24 are provided. Reference numeral 25 in FIGS. 4 to 6 is a toner scraping member that scrapes off toner adhering to the bell 17 and cleans it. The configuration other than the configuration is the same as that in FIG. 1. However, in the embodiment shown in FIGS. 4 to 6, since the belt] 7 comes into contact with the toner on the sleeve 7, the middle to (Vl)
The structure and operation of the membrane J2 explained in VC are as follows:
For example, regarding the material of the membrane mentioned in IVI vc, this can be considered as the material of the belt 17. 1, Figures 4 to 6
In the embodiments shown in the figures, it goes without saying that instead of using the magnetic fluid J1, a magnetic developer or other matrix powder may be used. [7] can be made of an appropriate material such as metal or synthetic resin, and this material may be either magnetic or non-magnetic, but if a magnetic material is used, the magnetic fluid J1 or magnetic powder Since the force drawn by the magnet 8 is reduced, in that sense it is advantageous to construct the membrane 12 and the belt 17 with non-magnetic material. Using one available on the market, the membrane J2 is 20 to 1
00 Mizo family, all sea lions, and N + with a thickness of less than 50μ,
Using a sheet such as Ou + SUS as appropriate, this film 12
The contact length ζL with the toner was set to about 25 mm, and an experiment was conducted to make the toner a thin layer and to charge it by friction.
However, compared to using a conventional doctor blade or elastic blade, the thickness of the first layer can be made even thinner, and the charge meter of the toner can also be increased. . Through this experimental laboratory, we were able to confirm that the l-ner can be controlled to a thickness ζ that is approximately one inch thick. 77 In each example, the layer thickness ζIL
In the embodiment shown in FIG. (elastic in example)
A roller-shaped base made of non-magnetic paulownia wood with 6
．． J-1 A layer thickness regulating member 27 made of magnetic fine particles (not shown) dispersed in this base body is used 9. The regulating member 27 is in contact with the surface of the developing sleeve 7 via the toner. Notes Magnetic particles (1-Shi is soft ferrite,
A ferromagnetic material such as permalloy or soft iron can be advantageously used, and the base 26 (!-) may be made of a synthetic resin with relatively low hardness, such as a synthetic resin with a rubber hardness of 2()0 or less, natural rubber, etc. (The configuration other than the 1rii thickness regulating means in Figure 2B7 is substantially the same as the configuration of the embodiment described above and shown in 2.) Also in this example, the magnetic fine particles , the base body 26 is elastically deformed to the surface of the sleeve 7 through the toner, and is drawn into the curved shape f (contacted with the toner) by the female magnet 8 disposed inside the viewing sleeve 7f. When the sword is applied, the layer thickness regulating member 27 is actually pressed against the sleeve 7 by the magnetic force. Alternatively, the member 27 may be pressed against the sleeve 7 with a predetermined pressure in advance, and the toner may be made into a thin layer by the cooperation of the pressing blade and the magnetic force. If the layer thickness regulating member 27 is rotatably supported and rotated at all times or as needed, streaks can be produced in the toner layer, as in the embodiments shown in FIGS. 4 to 6. This has the advantage of reducing the inconvenience caused by the restriction member 27. In this case, f1 is a toner scraping member that scrapes off toner that adheres to the circumferential surface of the member 27. ,
In an exceptional case, the scraping member 2'3 is constituted by the wall of the tank 6.
It goes without saying that the member 27 can also be advantageously used for the purpose of triboelectrically charging the toner to a predetermined polarity. According to an experiment, when the layer thickness regulating member 27 is configured to be constantly rotating and the member 27 is rotated in the opposite direction to the sleeve 7 in the same region as the sleeve 7, the toner becomes even thicker. In the configuration shown in Figure 7, the layer thickness regulating member ?7 is formed in the shape of a roller, which can be made into a flexible layer. 1p) t is elasticity Vt
It goes without saying that the same effect can be obtained even if the belt t5 is formed. In order to effectively thin the toner layer by attracting the lifting platform and the belt-shaped layer thickness regulating member with a relatively large knife using the magnet inside the sleeve, the thickness of the belt-shaped layer thickness regulating member must be Thickness, for example 1r
It is advantageous to increase the amount of MB magnetic particles that can be dispersed in the substrate by setting the thickness to n1n or more, but if the thickness ζ is too thick, the belt-like layer thickness regulating member will be difficult to deform, and this will prevent the toner on the sleeve from deforming. Therefore, the thickness of the layer thickness regulating member should be determined taking both of these factors into consideration, and although it varies depending on the quality of the regulating member, this thickness should be set to, for example, 5 mm@ It is advantageous to set it at the same time. 11, a belt-shaped layer thickness regulating member is wound around the roller 18 in the same manner as the belt i.]7 shown in FIG. 4, or the belt J7 shown in FIG. −
, :'i 20', 2], , 22 VC winding total 1
In order to obtain the same effect as the embodiment shown in FIG. 4 and FIG. Also, the same effect as that previously explained for (T, ) to Ml can be obtained. Therefore, for the reason stated in IM, from field-8-VC, the layer thickness regulating member 27 is made of a conductive material. Consisting of !: Advantageous. Layer thickness regulating member 27
The number of G is not limited to one, but may be plural. By using the developing device 2 shown in FIG. 27
Thinner the toner and increase the amount of charge! :around,
The toner density of sleeve 10 after regulation is 1.0 to]
, 3mg/l! 1771'% The amount of charge on the toner can be reduced by approximately 3μc/gK. The developer used was a high-resistance component type toner consisting of a styrene acrylic type l/I resin with a particle size of J2μ, a specific gravity of 1°83, and a Ti'e304 content of 1% and 50%. +9 property leveling agent/ζ. From now on, RIB clarifies the effect 1 of the non-inventive basic composition example. It can also be applied to other types of developing devices.For example, as shown in FIG. The structure consists of a left dielectric layer 30 and a large number of microelectrodes 31 supported by this, and these microelectrodes 3] are electrically insulated from the conductive support 29. Comrades are also practically insulated, @
A configuration has already been proposed, and by using this developing sleeve 7, it is possible to visualize a line image (linear latent image) of an electrostatic layer image with a particularly high density, and therefore it is possible to visualize a relatively It is possible to obtain a visible image of low density from a thin line image of low density (Japanese Patent Application No. 885726/1983).In order to obtain this effect, it is necessary to Although it is necessary to make the gap extremely narrow and the amount of charge on the toner thick, the uninvented layer thickness regulating means 9
By using this method, these requirements can be satisfied almost simultaneously, and the invention can therefore be advantageously applied to a developing device having a developing sleeve as shown in FIG. In this case, the control means 9 If (therefore, the toner is charged is -(-y
Try to avoid C! - It is advantageous that the toner is charged by friction between the toner and the developing sleeve, and preferably, the toner is not charged by friction between the regulating means 9 and the toner. If you do this,
The microelectrode 31 in the developing sleeve 7 is charged to the opposite polarity to that of the toner, and when the microelectrode 3 reaches the developing area, it acts just like the carrier in the two-component developer VC, and the photoconductor This is because it pulls back the toner adhering to the skin from the skin, thereby effectively suppressing the occurrence of so-called skin stains. In the illustrated embodiment, a magnet 8 is used as the kth magnetic field generating means 2 for attracting magnetic fluid, magnetic powder, or magnetic fine particles. Of course o′! The FFC invention can be applied not only to a developing device that generates a rotating magnetic field, but also to an equalizing device that simply generates a magnetic field.
Generating a rotating magnetic field using an electromagnet -J-! The layer thickness regulating means 9 and the developing sleeve 7,! During the period between 1 and 2, foreign matter in the toner, such as thread, is clogged.
It is advantageous to reduce the specific π. Good luck generating a rotating magnetic field,
The toner between the sleeve and the regulating means vibrates in the normal direction of the sleeve, and as a result, foreign matter in the toner floats to the surface of the toner. This is because it is easy to escape. In each of the above embodiments, an example is shown using a leveling agent made of a high resistance magnetic toner. A developing device using a developer consisting of a developer or a two-component developer is also applicable. In this case, even when the invention is applied to a developing device using a non-magnetic developer, it is necessary to install a magnetic field generating means in the developing sleeve to attract magnetic fluid, magnetic powder, or magnetic fine particles with magnetic force. However, the magnetic field generating means in this case does not have the function of transporting the developer (G). Furthermore, the invention can be modified in various ways to the extent that is obvious to those skilled in the art. For example, the invention can be applied to the developing sleeve, the developer of a developing device using a heddle-like developer carrier, and the invention can be applied to the final latent image carrier. The invention can also be advantageously applied to developing devices such as direct copying machines used for copying, electrostatic recording devices, and magnetic printers that form latent images using magnetism.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a specific example of a developing device according to the present invention;
FIG. 2 is an explanatory diagram schematically showing the toner present between the developing sleeve and the film, FIGS. 3 to 7 are cross-sectional views showing other specific examples of the developing device, and FIG. 8 is a microelectrode. FIG. 2... Developing device 9... Layer thickness regulating means ]]...
Magnetic Fluid Figure 1 1-A 3 5a 9, y2 S-2° Ding,-1 and Fight, Ni 2: 10 4 L 2 Tsui and 2~S
S −−~g−=−= 1+5 − N
〜〜〜〜 °C−−−、−6−−−−−〜〜 °I−1, change from knee high socks to saw Figure 3 Figure 2 Figure 21 Figure 6 Figure 7 Figure 8] 1

Claims (8)

[Claims] (1) A developer carrier for carrying a developer, a layer thickness regulating means for regulating the layer thickness of the developer on the developer carrier, and an fc magnetic field generating means disposed inside the developer carrier. Contains and the layer thickness is regulated7? - In a developing device that conveys a developer to a development area where a latent image is visualized and visualizes the latent image, the layer thickness regulating means comprises a magnetic material having fluidity; The developing device further comprises at least one flexible member disposed between the magnetic tray and the developer carrier. (2) The developing device according to claim 1, wherein the magnetic material having fluidity is a magnetic fluid. (3) The developing device according to claim 1, wherein the magnetic material having fluidity is magnetic powder. (4) The developing device according to claim 3, wherein the magnetic powder is a developer used in the developing device. (5) A developer carrier that carries a developer, a layer thickness regulating means for regulating the layer thickness of the developer on the developer carrier, and a magnetic field generating means disposed inside the developer carrier. In a developing device that controls the layer thickness and feeds a developing agent to a developing region where a latent image is visualized, At least one layer thickness regulating member consisting of a base made of a magnetic material and magnetic fine particles dispersed in the base is used as the layer thickness regulating means, and the layer thickness regulating member supports the developer via the developer. The developing device is arranged to face the body. (6) The developing device according to claim 5, wherein the layer thickness regulating member is formed in a roller shape. (7) The developing device according to claim 5, wherein the layer thickness regulating member is formed in a belt shape. (8) The imaging device according to any one of claims 5 to 7, wherein the layer thickness regulating member is movably supported.